Most individuals now, or in the near future will, have at least two telephone numbers through which they make or receive calls on a regular basis. One of these telephone numbers is usually associated with a fixed network while the other is usually associated with a cellular network. The connectivity from the local access provider is to the traditional fixed telephone network (oftentimes referred to as the Public Switched Telephone Network (PSTN)) while the connectivity from the cellular service provider is to the cellular network (CN). Increasingly, local access providers are also cellular service providers and vice versa. As a result, it is anticipated than many telecommunication users will have the same service provider for their fixed and cellular service. For discussion purposes below, let N.sub.f and N.sub.c respectively denote the telephone number for a particular user to the fixed and cellular network.
The calls made from N.sub.f are usually of lower cost than those made or received from N.sub.c because the call is routed over the fixed network and therefore does not make use of the limited wireless bandwidth. However, once a call has been initiated on the fixed network, the user has very little mobility; a cordless phone may allow the user to move 50-100 meters from the base of the phone without significant deterioration in the voice quality. However, a user can move in a wide geographical area if a user could forward an on-going call originated over the fixed network to the cellular network. A point of departure from the prior art in accordance with the present invention is a new call forwarding service called the Forwarding On-going Call Service (FOCS) to allow users to complete and then forward on-going calls between his/her fixed and cellular telephone numbers at the request of the user.
The FOCS service benefits both the user and the service provider. The user benefits because he/she can use the lower cost calls through the fixed network whenever possible without sacrificing mobility. The service provider also benefits because as users switch over to fixed network from cellular whenever possible, the limited capacity of the cellular network can support other users. More customers will also be attracted to this lower cost service with full support for mobility.
Heuristic Example 1
Suppose that a user receives a call at home on N.sub.f just as she is about to leave for work. At present, the user has only one of the following two options. Either complete the call before starting the commute to work or terminate the conversation and restart it using the cellular phone. Terminating the conversation and restarting it using the cellular phone requires all parties in the call to hangup and reestablish the necessary connections. This is clearly troublesome.
However, if the user can forward the call over to her cellular telephone without disrupting the conversation, then the call can be continued while the user is in commute. Thus, the user benefits because she gets mobility while using the lower cost of the fixed network for as long as possible.
Heuristic Example 2
Suppose that a user makes a call using his cellular telephone while away from home and comes back home while the call is in progress. There will be no degradation in the voice quality and the user can continue using the more expensive cellular network while at home. However, if the user can forward the call to his fixed telephone, the cost of the rest of call will be lower. The service provider will also benefit because as users switch over to the fixed network, the limited capacity of the cellular network can be used to support other users.
The prior art does not allow forwarding of on-going calls from a fixed network to a cellular network and vice versa. Some service providers offer forwarding of calls from the fixed to the cellular network prior to the establishment of a call, such as by conventional call-forwarding. Similarly, some fixed network service providers offer forwarding of on-going calls from one fixed telephone number to another number, typically at the request/intervention of the called party.